This application relates to protective eyewear of the type worn by medical, surgical, dental, and other healthcare professionals, and particularly eyewear that allow users to maintain ideal, healthy working posture while simultaneously providing ideal working vision. The terminology “eyewear” includes “eye glasses”, “loupes”, “goggles”, “safety glasses”, “smart glasses”, “protective eyewear”, and other types of wearable devices worn over the eyes.
Doctors, Surgeons, Dentists, and other healthcare professionals often need to work on a patient or device that requires use of the hands below the normal level of eye sight. FIG. 1(a) illustrates an example of a doctor (111) working on a patient (102) using traditional protective eyewear (112). The Working Declination Angle (WDA), is defined as the angle between the horizontal plane and the line from the viewer's eyes to the working area. Here, the horizontal plane is used to approximate a viewer's unstrained, straight viewing direction while sitting or standing with healthy posture. The Working Declination Angle (WDA) is often larger than 60 degrees. Using traditional protective eyewear (112), the doctor (111) needs to bend the head, neck, and back, and/or use excessive downward eye tilt in order to view the working area clearly, as shown in FIG. 1(a). The doctor (111) frequently needs to hold this uncomfortable and unhealthy posture for long periods of time throughout a working day. Such unfavorable working posture frequently results in back, neck, shoulder, and/or eye strain, causing fatigue that can degrade the quality of the operation and also lead to chronic health problems for the professional.
The most common prior art solution for this problem is to wear specialized eyewear (122) using loupes or magnification eye pieces (124) arranged in an Eyewear Declination Angle (EDA), as illustrated in FIG. 1(b). The Eyewear Declination Angle (EDA) is defined as the angle between the eyewear viewing direction and the viewing direction of the image capturing device(s) on the eyewear, as illustrated by the example in FIG. 1(b). The eyewear viewing direction is defined as the unstrained, straight viewing direction through the eyewear, approximately parallel to the horizontal plane when the user sits or stands with ideal, healthy posture. An image capturing device can be an eye piece, camera, or other optical and/or electronic device. For the case in FIG. 1(b), the required working declination angle (WDA) is the same as that in FIG. 1(a), while the eyewear declination angle (EDA) of the magnification eye pieces (124) allows the doctor (121) to view working areas with less bending of the neck and back, as illustrated in FIG. 1(b). However, due to space limitations, the achievable eyewear declination angle (EDA) of the magnification eye pieces (124) is typically limited to be smaller than the required working declination angle (WDA). Furthermore, use of such specialized eyewear (122) still requires the user to strain the eyes in a downward direction. It provides a partial solution to the problem, but it does not solve the problem adequately. Professionals are still required to strain the back, neck, shoulders and/or eyes to achieve proper working vision, though to a lesser degree when compared with the traditional protective eyewear in FIG. 1(a).
Chang in U.S. Pat. No. 9,465,235 disclosed a through-the-lens loupe with improved eyewear declination angle. Holes are opened on the viewing windows of the eyewear to allow larger built-in eyewear declination angles. However, the angle is still not large enough to allow the doctor to maintain ideal ergonomic posture while working.
Fante et al. in U.S. Pat. No. 7,542,204 disclosed a method to improve eyewear declination angle using optical deflectors. The resulting microscopes are larger and heavier than the prior art example in FIG. 1(b). Fante may help reduce problems caused by the working declination angle, but the added weight of the deflectors may also cause ergonomic problems.
Fujie et al in U.S. patent application Ser. No. 11/090,820 disclosed a system for dental diagnosis and treatment that includes an intraoral camera which can capture moving images in the patient's oral cavity, and the camera can be fixed near the patient's mouth. The image captured by the intraoral camera is displayed on a TV screen or monitor installed at a position where the dentist can see. Using video image processing methods, the system can invert the image in the vertical direction and reverse the image in the lateral direction. The capabilities of Fujie's image processing are limited to image reversion. Additionally, the image is taken from an intraoral camera directly facing the mouth of a patient, which is not the same position of view from which dentists are familiar with working. Using this system, dentists need to operate with a different field of view than that with which they are trained. Furthermore, images displayed on the monitor are two-dimensional views which lack depth perception. Depth perception is defined as the visual ability to perceive the world in three dimensions, the ability to judge the distance of objects, and the ability to perceive the spatial relationship of objects at different distances. This information is critical for operations requiring precise hand-eye coordination. Fujie may help reduce the ergonomic problems caused by unfavorable posture, but with this system, users need to spend time re-training themselves to operate in an unfamiliar manner.
Garofolo et al in U.S. Pat. No. 9,690,119 disclosed a device that is equivalent to a virtual reality eyewear with an added centered camera system. Images of a working area captured by the centered camera are displayed on the screen of the virtual reality eyewear, allowing the user to view the working area in an ergonomically healthy posture. However, a centered optical system cannot provide three-dimensional views with accurate depth perception. It lacks the features to support professional operations that require a high level of hand-eye coordination. This complicated high-technology virtual reality eyewear also creates a working environment that is not familiar for doctors. The added weight of the virtual reality eyewear also can cause ergonomic problems.
These prior art devices provide partial solutions to the problem, but they do not solve the problem adequately. It is therefore desirable to provide eyewear for medical, surgical, dental, and other healthcare professionals that can allow them to treat patients from the same doctor-patient positions with which they have been trained, while simultaneously operating with ideal ergonomic posture. Other professionals who are required to work below the normal level of eye sight, such as dental hygienists, veterinarians, and laboratory technicians, will also benefit from this invention. It is essential that the view provided by the eyewear can accurately represent the three-dimensional view with accurate and natural depth perception, to which healthcare professionals are accustomed. It is additionally essential that the eyewear can provide additional working aids using image processing technology and audio signal processing technology.